US4076879A - Sheet material - Google Patents

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Publication number
US4076879A
US4076879A US05/616,714 US61671475A US4076879A US 4076879 A US4076879 A US 4076879A US 61671475 A US61671475 A US 61671475A US 4076879 A US4076879 A US 4076879A
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United States
Prior art keywords
skin
sheet
product
adhesive
microns
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US05/616,714
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English (en)
Inventor
Stuart Paul Suskind
Stanley George Sova
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BASF Corp
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Inmont Corp
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Priority to CA237,018A priority Critical patent/CA1079170A/fr
Priority to US05/881,102 priority patent/US4229472A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/10—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of paper or cardboard
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/007—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by mechanical or physical treatments
    • D06N3/0077—Embossing; Pressing of the surface; Tumbling and crumbling; Cracking; Cooling; Heating, e.g. mirror finish
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/0002—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the substrate
    • D06N3/0015—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the substrate using fibres of specified chemical or physical nature, e.g. natural silk
    • D06N3/0025—Rubber threads; Elastomeric fibres; Stretchable, bulked or crimped fibres; Retractable, crimpable fibres; Shrinking or stretching of fibres during manufacture; Obliquely threaded fabrics
    • D06N3/0027—Rubber or elastomeric fibres
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/0002—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the substrate
    • D06N3/0015—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the substrate using fibres of specified chemical or physical nature, e.g. natural silk
    • D06N3/0025—Rubber threads; Elastomeric fibres; Stretchable, bulked or crimped fibres; Retractable, crimpable fibres; Shrinking or stretching of fibres during manufacture; Obliquely threaded fabrics
    • D06N3/0031—Retractable fibres; Shrinking of fibres during manufacture
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/18—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with two layers of different macromolecular materials
    • D06N3/183—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with two layers of different macromolecular materials the layers are one next to the other
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/02—Synthetic macromolecular fibres
    • B32B2262/0292—Polyurethane fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2601/00—Upholstery
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/904—Artificial leather
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24058—Structurally defined web or sheet [e.g., overall dimension, etc.] including grain, strips, or filamentary elements in respective layers or components in angular relation
    • Y10T428/24124—Fibers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24355—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
    • Y10T428/24438—Artificial wood or leather grain surface
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24942—Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree
    • Y10T428/2495—Thickness [relative or absolute]
    • Y10T428/24967—Absolute thicknesses specified
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24942—Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree
    • Y10T428/24992—Density or compression of components
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249987—With nonvoid component of specified composition
    • Y10T428/249991—Synthetic resin or natural rubbers
    • Y10T428/249992—Linear or thermoplastic
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
    • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
    • Y10T442/674—Nonwoven fabric with a preformed polymeric film or sheet
    • Y10T442/675—Ester condensation polymer sheet or film [e.g., polyethylene terephthalate, etc.]

Definitions

  • This invention relates to sheet products particularly suitable for use in upholstery and to sheet products especially suited for use as shoe upper material.
  • a thin substantially non-porous preformed elastomeric skin (preferably of polyurethane) is adhered to a base sheet of criss-crossing elastomeric polyurethane fibers running parallel to the surfaces of the sheet, said fibers being bonded together at their points of contact.
  • the preformed skin has a thickness of less than about 100 microns and preferably less than about 50 microns, such as about 20 to 40 microns.
  • the production has a substantially nonporous upper zone joined to the fibers of the base sheet by spaced fingers of adhesive.
  • the present invention provides, in one aspect, a flexible, durable leatherlike sheet material particularly suitable for upholstery of household furniture and automobile furniture (i.e. seats) where the appearance and tactile qualities of soft leather are desirable.
  • Polyurethane coated fabrics designed for these markets are known to the art. They are typically comprised of a urethane film bonded to a napped woven or knit substrate. These materials are notoriously poor in snag and mar resistance, are anisotropic and are deficient in tear and seam strength in one direction, and generally lack the durability required for these applications. Attempts to improve these deficiencies have been met with limited success usually resulting in a loss of flexibility, softness and related aesthetic properties.
  • the present invention provides a new coated fabric with greatly improved surface toughness and tear properties over prior art combined with the supple, flexible qualities of natural leather. Furthermore, the present invention provides a unique product having multidirectional stretch and conformability required in upholstering complex modern furniture.
  • the fibrous base sheet of criss-crossing elastomeric polyurethane fibers running parallel to the surfaces of the sheet and bonded together at their points of contact is produced in the manner described in Fine and deTora application Ser. No. 486,567 filed July 8, 1974 (published German patent application No. 2,207,725 and British patent No. 1,383,597).
  • FIGS. 1-9 and corresponding FIGS. 1A-9A are photomicrographs (made with a scanning electron microscope) of cross-sections of the product, the cross-sections being obtained by cutting perpendicularly through the thickness of each sheet with a razor.
  • the scanning electron microscope has a great depth of focus enabling one to, in effect, see into the interior of the structure.
  • the white bands seen at the top of the structures result from reflections from portions of the upper surface of the skin beyond the plane of the cross-section.
  • the undulating or irregular surface of the skin is due, in part, to the fact that the release paper has an embossed "grain" (its surface is irregular so as to impart to a skin cast thereon a topography simulating that of grained leather, as is conventional in the art).
  • the scale for FIGS. 1-9 is shown next to FIG. 1; the scale for FIGS. 1A-9A (which correspond to FIGS. 1-9, respectively, but are taken at greater magnification) is shown next to FIG. 1A.
  • Further discussion of scanning electron photomicrographs is found, for instance, in Civardi et al U.S. Pat. No. 3,764,363, which also discusses leather-like "break".
  • FIGS. 1B-9B are graphical tabulations based on rough measurements made on FIGS. 1-9 respectively, to indicate the solids proportions at various levels of the structure.
  • the ordinate indicates the linear proportion of solid (in the plane of the cross-section of the sample) found in the line on which the measurement is made, while distances along the "x" axis show the distances, in the sample, between the lines along which the measurement were made. For instance in making the measurements for FIG. 1B the technician laid a straight edge horizontally across the photograph (FIG.
  • FIGS. 1 and 1A illustrate a product made (as described more fully in Example 1 below) by forming a solid elastomeric polyurethane skin 11 having a dry thickness of about 45 microns on temporary support (conventional release paper) then applying a layer of adhesive (a solution of elastomeric polyurethane in volatile solvent) on the skin, applying the adhesive to the sheet 12 by bringing the wet adhesive layer into face-to-face contact with one surface of the fibrous sheet 12 and passing the assemblage (or release paper, skin, adhesive and fibrous sheet) through the nip of a pair of high pressure squeeze rolls, then evaporating off the solvent by heating, and mechanically stripping off the release paper.
  • adhesive a solution of elastomeric polyurethane in volatile solvent
  • the squeeze rolls may comprise a roll having a fixed axis and a cooperating pressure roll which is forced toward the other roll, as by a suitable weight or hydraulic cylinder).
  • the resulting product is not a preferred material, e.g. as a substitute for soft upholstery leather; it does not show a leather-like break.
  • the adhesive has formed a layer 13, which is unitary with the original skin layer 11, (and is distinguishable therefrom in the photographs by a slight difference in shade) and that the adhesive has not penetrated much into the structure of the fibrous sheet.
  • the combination of skin and adhesive forms a substantially non-porous layer whose thickness is well over 70 microns (as can be measured on FIG.
  • FIG. 1B indicates that along the straight horizontal line 3--3 the proportion of solid (in the plane of the cross-section) is 80-90%; along a line 60 microns above 3--3 it is substantially 100% (not shown in FIG. 1B), along the line spaced 30 microns below 3--3, it is only about 50%; along lines spaced 120 microns or more below 3--3 it is well below 40% as is characteristic of the untreated fibrous base.
  • FIGS. 2 and 2A illustrate a product made (as described more fully in Example 2 below) in a manner similar to the product of FIG. 1, using a polyurethane latex adhesive and applying no nip pressure to the assemblage.
  • the product does not have a good leather-like break.
  • the original skin layer 16 has been supplemented by an integral adhesive layer 17 so that the thickness of the non-porous zone is about 100 microns or more, and that there is substantially no penetration of adhesive into the fibrous sheet.
  • FIG. 2B illustrates the pattern illustrated in FIG. 2B; it will be understood that since the upper surface in FIG. 2 is tilted the parallel lines used for these measurements are similarly tilted.
  • the point marked "g" on FIG. 2B is the measurement taken along a straight line generally parallel to the effective skin 16-17 and passing through the depending protuberances P and P 1 . The other measurements are taken along lines parallel to that straight line.
  • FIGS. 3 and 3A illustrate a product made (as described more fully in Example 3 below) in a manner similar to the product of FIG. 1 but applying a polymer latex to the surface of the fibrous sheet to "prefill" a surface zone of that sheet before the solvent based adhesive is applied to the sheet.
  • an adhesive layer 22 which is porous and of low specific gravity, having relative large bubbles 23. At least some of these bubbles seem to be communicating with other bubbles; the bubbles may result from temporary trapping of solvent vapors during the heating step.
  • the product has a "hand” like that of soft leather and exhibits a desirable fine leather-like break.
  • the point "h” represents the measurement along a straight horizontal line just passing through the tops of the bubbles 23, and the other points represent measurements along lines spaced below the first line and parallel thereto. It will be seen that there is a sharp drop in the linear proportion of solids just below the skin and that the solids content in the underlying zone is somewhat higher than that in FIG. 1B indicating that the adhesive has penetrated to a distance of considerably more than, say, 100 microns below the skin. The linear proportion of solids in the zone about 100 to 200 microns below the skin is generally below about 50%.
  • FIGS. 4 and 4A illustrate a product made (as described more fully in Example 4 below) in a manner similar to the product of FIG. 1 using an elastomeric polyurethane latex adhesive which is applied to a damp (pre-wet) fibrous sheet.
  • the thin skin 24 (about 20 to 30 microns thick) is joined to the fibrous sheet by fingers or "roots" 25, 26, 27 of adhesive which penetrate into the upper zone of the fibrous sheet and which increase or reinforce the fiber-to-fiber bonding.
  • the product has a very good leather-like feel and break.
  • Point "o” represents a measurement made along a straight horizontal edge situated at the equivalent of another 30 microns (measured along the right hand boundary of the photograph) below the last (lowest) position of the wavy edge. All the other points represent measurements along straight horizontal lines parallel to that used for measuring point "o". It will be seen in FIG. 4B that the linear proportion of solids drops sharply below the skin and then remains generally higher than about 30% (but generally lower than about 50%) for a further distance of considerably more than 100 microns below the skin, again indicating penetration by the adhesive.
  • FIGS. 5 and 5A illustrate a product made (as described more fully in Example 5 below) in a manner similar to the product of FIG. 1 using an elastomeric polyurethane latex adhesive which is applied to a dry fibrous sheet.
  • the skin is joined to the fibrous sheet by the fingers or roots of adhesive but the substantially non-porous zone is thicker because of the presence of an almost continuous layer of adhesive so that, over a major portion of the area of the sheet, the thickness of that zone is about 50 microns. While the product is useful for many purposes it is inferior to that of FIG. 4 in its feel and break.
  • FIG. 5B indicates that the linear proportion of solids remains relatively high (above about 50%) even in the zone that is some 100-200 microns below the non-porous zone.
  • FIGS. 6 and 6A illustrate a product made (as described more fully in Example 6 below) in a manner similar to the product of FIG. 1 using an elastomeric polyurethane latex which is applied to a dry fibrous sheet and using a stop to limit the travel of the pressure roll so that the roll surfaces can approach each other no closer than, say, about 10 to 20 mils (about 250-500 microns) plus the thickness of the release paper.
  • This modification yields a structure in which the thickness of the original skin is scarcely increased by the presence of the adhesive, the total non-porous zone thickness being generally below about 50 microns and that zone being joined to the fibrous sheet by spaced fingers or roots 28, 29, 30, 31 which do not increase the solids proportions in the next underlying zone to nearly the extent found in FIG. 5.
  • these fingers are so spaced that their bases, at said non-porous zone, comprise well below one half (such as 1/3 or less) of the length of the skin.
  • the product has very good leather-like feel and break.
  • the first four measurements just below that zone for FIG. 6B were made with an edge conforming to that zone (having the configuration indicated as "s" adjacent to FIG. 6B) and the resulting points are indicated by crosses.
  • the next measurements were made with a straight horizontal edge, the first such measurement being made with the horizontal edge situated the equivalent of some 10 microns (measured along right hand boundary of the photograph) below the last (lowest) position of the wavy edge.
  • a sharp drop e.g. to a linear solids proportion below 50% (such as about 30%) just below the non-porous zone and the solids proportion remains in the range of about 30-60% for a considerable distance below that zone.
  • FIGS. 7 and 7A and 8 and 8A show products made by a method like that used for FIG. 6, with fibrous sheets of different densities; see Examples 7 and 8, respectively, for details.
  • FIGS. 7B and 8B there are shown measurements made along straight horizontal lines starting at the equivalent of about 100 microns below the skin.
  • the linear solids proportion in the zone some 100-200 microns below the skin is in the range of about 50-70%; in FIG. 8B it is in the range of about 35% to 50 or 60%.
  • FIGS. 9 and 9A illustrate a product made, without adhesion, by forming and depositing fibers directly onto the skin, using the skin (on the release paper) as the collecting surface in the process described in said Fine and deTora application.
  • the product has a good leather-like break but its abrasion resistance is significantly lower than that of the products of, say, FIGS. 3, 4, 6, 7 and 8. It would appear that the skin in FIGS. 9 and 9A is not nearly as well bonded to the upper fibers and/or the latter are not nearly as well bonded to their contacting fibers as when the adhesive is present and thus the skin is not reinforced to the same degree. It will be seen that in this particular sample there are distinct areas where fiber formation is incomplete.
  • the points represent measurements along straight horizontal line the first such line being just below the skin.
  • the lower portions are of relatively low density such as below 0.4 g/cc or lower, e.g. about 0.2 to 0.3 g/cc.
  • the polyurethane of the base sheet is typically a polyether polyurethane made, in 20% solution in tetrahydrofuran in conventional manner, from poly-tetramethyleneglycol of average 1000 average molecular weight, 1,4-butanediol and 4,4'-diphenylmethane diisocyanate and having a nitrogen content of 41/2%, a number average molecular weight of 25,000 and an intrinsic viscosity (measured at 25° C in tetrahydrofuran) of 1.070; when a film is cast therefrom it typically has a tensile strength of 4300 psi, an ultimate elongation of 470% and a 25% modulus of 646 psi.
  • the base sheet is produced in the manner described in the aforementioned Fine and deTora application.
  • the skin is formed by applying, to a support having a surface which resists adhesion (e.g. conventional release paper), a coating of a solution of elastomeric polyurethane in a volatile solvent and evaporating the solvent.
  • a 35% solution of a polyester-polyurethane such as a commercial material known as Witcobond Y-343 (from Witco Chemical) which is a 35% solution of light-stable aliphatic polyurethane elastomer in a mixed solvent (25% dimethylformamide, 35% isopropyl alcohol, 15% toluene, 25% methyl cellosolve), the polyurethane having an elongation at break of 475%, a softening point of about 250°-300° F, a tensile strength of about 5000-7000 psi (ASTM D-412), its moduli at 100%, 200% and 300% elongation being 800, 1100 and 2000 psi respectively, said solution also containing dispersed therein antimony trioxide and "BP-6" (hexabromobiphenyl) as flame retardants, together with pigments (the ratios of polymer to antimony trioxide, PB-6, and pigment being respectively, about 20:1,
  • the coated release paper may then be passed through an oven, at, say, about 300°-325° F to remove substantially all the solvent.
  • an adhesive is used the release paper carrying the skin is then coated with a thin layer of the adhesive.
  • This may be a solution (e.g. in a volatile solvent) or a dispersion, such as a viscous latex.
  • a dispersion such as a viscous latex.
  • One may employ, as the latex adhesive, an aqueous dispersion of an elastomeric polyurethane ionomer of the cationic or anionic type (such as described, for instance, in the article by Dieterick, Keberle and Witt "Polyurethane Ionomers, a New Class of Block Polymers" in Angew. Chem. Intern. Edit. Vol. 9 (1970) No. 1 p. 40-50 and references cited therein.
  • a thickening agent such as a water-soluble high polymer may be included to increase the viscosity
  • the adhesive is a two-component solvent-based adhesive of conventional type containing a mixture of 150 parts of a low molecular weight polyurethane having alcoholic hydroxyl end groups (Impranil C) and 22.4 parts of a low molecular weight curing reactant having terminal isocyanate groups (Mobay CD-75 or Vorite 144, an adduct of toluene diisocyanate and trimethylolpropane) in 350 parts of solvent (a mixture of equal parts of dimethylformamide and methyl ethyl ketone) containing 7.5 parts antimony trioxide, 7.5 parts BP-6 (hexabromobiphenyl) and 46.4 parts of a concentrated dispersion of pigments in methyl ethyl ketone.
  • solvent a mixture of equal parts of dimethylformamide and methyl ethyl ketone
  • the adhesive is applied as a layer 7 mils thick (wet thickness) to the skin on the release paper; the fibrous sheet is immediately placed on the wet adhesive layer and the assemblage is immediately passed through the nip of the squeeze rolls. and then passed into drying ovens (e.g. at up to about 300° F) to remove solvent, after which the release paper is stripped off.
  • drying ovens e.g. at up to about 300° F
  • Example 1 is repeated using a substrate having a density of about 0.27 g/cc and a thickness of 31 mils, and a latex adhesive, deposited at a wet thickness of about 8 mils.
  • the adhesive is a mixture of 110 parts Impranil DLN Dispersion (a milky latex containing 40% anionic thermoplastic aliphatic polyester polyurethane and having a pH of 6 to 7, a particle size of 0.1 to 0.2 micron and a viscosity of 220 cps, measured with Brookfield LVG type at 20° C, Spindle No.
  • Impranil Thickener PW an aqueous solution of polyvinylpyrrolidone
  • Oncor 75 RA a fire retardant composed of silica-treated antimony trioxide
  • the polyurethane in Impranil DLN is one which, in a 0.1 mm thick film, has an ultimate tensile strength of about 3550 psi, an elongation at break of 700%, a 100% modulus of 270 psi and a Shore A hardness of 60, and volume swell values at room temperature of 450% in trichloroethylene, 10% in water and 250% in perchloroethylene. No nip pressure is used in making the laminate; the latter is dried in an oven at 250° F (e.g. for 3 minutes) before stripping off the release paper.
  • Example 1 is repeated except that the surface of the fibrous sheet is "pre-filled” (as described below) before it is brought into contact with the wet solvent-based adhesive.
  • a latex of a polyurethane elastomer is applied to the surface of the fibrous sheet and dried thereon. More particularly the following latex is employed: a mixture of 450 parts of Geon Latex 660 ⁇ 2 (49.1% non-volatiles, a dispersion of polyvinyl resin), 162 parts of water and 135 parts of Carboset K718 (sodium polyacrylate solution in water, a thickener).
  • the latex is metered onto the fibrous sheet by first depositing a 5 mil thick (wet thickness) layer of the latex onto release paper, then bringing the surface to be pre-filled into contact with the wet latex layer while the substrate is damp (having been wet-out and squeezed as in Example 4, below) then applying pressure to the assemblage, allowing the assemblage to stand for 1 minute at room temperature, mechanically separating the release paper from the resulting assemblage, and drying the prefilled substrate (e.g. at 300° F for 3 minutes); the latex is attracted to, and penetrates, the fibrous sheet, and the release paper strips off easily with substantially no retained latex thereon.
  • a 5 mil thick (wet thickness) layer of the latex onto release paper then bringing the surface to be pre-filled into contact with the wet latex layer while the substrate is damp (having been wet-out and squeezed as in Example 4, below) then applying pressure to the assemblage, allowing the assemblage to stand for 1 minute at room temperature, mechanically separating the release paper from
  • the prefilling step may be controlled (by routine, simple trial-and-error experiments) in relation to the other steps to avoid creating a pre-filled zone which is so solvent-impermeable that the solvent attacks the skin layer, forming holes in the skin, and also to avoid creating pre-filled zone that is so permeable as to give an effect like that of FIGS. 1 and 1A instead of the porous adhesive zone such as shown in FIGS. 3 and 3A.
  • Example 1 is repeated using a substrate having a density of 0.30 g/cc and a thickness of 37.4 mils and a latex adhesive deposited at a wet thickness of about 7 mils.
  • the adhesive is the same as that used in Example 3 except that the proportions are 100 parts of the Impranil DLN Dispersion, 5.7 parts of the Impranil Thickner PW and 13.4 parts of the Oncor 75RA.
  • the sheet Before bringing the fibrous base sheet into contact with the wet adhesive layer the sheet is wet with water containing 0.1% surfactant (namely dioctyl sodium sulfosuccinate) by squeezing it, and then releasing the pressure while contacting its surface with water, as by passing it through the nip of a pair of rolls beneath the surface of the water bath, so that on re-expansion after squeezing the sheet takes up, say, about 80-100% of water, based on its dry weight; after leaving the bath the wet sheet is squeezed so that it retains some 25-35% (based on its dry weight) of water.
  • the resulting damp sheet is placed on the wet adhesive and the resulting assemblage is passed through the nip.
  • the laminate is dried in an oven at up to 325° F to evaporate the water, before stripping off the release paper.
  • the laminate is then colored (by printing) and top-coated (with a very thin layer of elastomeric polyurethane).
  • Example 1 is repeated using the latex adhesive of Example 4.
  • the wet thickness of the deposited adhesive layer is about 8 mils and the drying thereof is carried out at 300° F.
  • the substrate used in this Example has a density of about 0.33g/cc and a thickness of 33 mils.
  • Example 1 is repeated using the latex adhesive of Example 4 and using a stop to prevent the pressure roll from approaching the fixed-axis roll closer than a distance of about 250 microns (10 mils), plus the thickness of the release paper.
  • the substrate used in this Example has a specific gravity of about 0.26g/cc and a thickness of about 39 mils.
  • the laminate is then colored (by printing) and top-coated (with a very thin layer of elastomeric polyurethane).
  • Example 6 is repeated using a substrate having a density of 0.22g/cc and a thickness of about 49 mils, the adhesive being deposited at a wet thickness of about 10 mils, the drying effected at about 300° F.
  • Example 7 is repeated using a substrate having a density of 0.27g/cc and a thickness of about 41 mils.
  • Preferred products of this invention have high elongations at break, generally well over 200%, such as in the range of 300-500%, e.g. 350-450% and high trapezoidal tear strengths, such as above 10 pounds, and they are substantially isotropic.
  • the preformed skin has a thickness in the range of 20 to 50 microns and has a 100% modulus about the same as that of the material of the underlying base sheet (as when the ratio of the 100% modulus of the skin to that of the base sheet material is in the range of about 1:2 to 3:2 such as about 0.7:1 to 1:1) and when the adhesive joining the skin to the base sheet has a lower 100% modulus than that of skin or base sheet material (such as a 100% modulus which is 2/3 or 1/3 or 1/4 of that of the base sheet).
  • a skin having a modulus below about 1400 psi, such as about 800 psi has given very good results, with an adhesive having a 100% modulus below 800, such as below 600 psi.
  • an adhesive having a 100% modulus below 800 such as below 600 psi.
  • One suitable adhesive has a 100% modulus below 500 psi, such as about 200 to 400 psi, while the use of a skin having a 100 % modulus of, say, 2000 psi has yielded a less desirable stiffer product which after stretching (e.g.
  • the adhesive may, with the preformed skin, form a two-layer substantially non-porous upper zone; in preformed forms of the invention these two layers (when present) have different stretch characteristics, the lower, adhesive-derived, layer being of more yielding material (as indicated by the 100% modulus).
  • the adhesive (as in the form of fingers of adhesive) may reinforce the fiber-to-fiber bonds (e.g. an adhesive finger adhering to two contacting fibers) or even create additional fiber-to-fiber bonds; in preferred forms of the invention such reinforcement or new bonds may be more yielding than the original bonds.
  • the skin is preferably of pigmented polymer of a type resistant to ultra-violet, such as an aliphatic (including cycloaliphatic) polyurethane; such polymers are well known in the art.
  • the fibrous base sheet may be of light-sensitive polymer, such as known aromatic polyurethanes and is protected from attack by the light-resistant skin.
  • the thickness of the upper substantially non-porous zone of the product is preferably less than about 100 microns and, in certain preferred forms of the invention, the structure is characterized by the presence of large voids whose dimensions (viewed in cross section) are at least about 30 microns by 30 microns occupying at least about one third (such as about one half or more) of the zone just below said non-porous zone.
  • release papers for forming polyurethane skins for subsequent adhesion to a substrate are well known in the art. See, for instance, U.S. Pat. Nos. 3,574,106; 3,650,880; 3,684,637; and published application T896018 (ser. 111,654 filed 2-1-71, 896 O.G. 19).
  • the release paper preferably has a topography such to produce a cast-embossing, such as a leather-like grain, on the surface of the skin cast thereon.
  • Release paper is commercially available in many such grain patterns, such as "buffalo”, “gloveskin”, “kid grain”, “hi calf”, “box calf”, continental calf”, “scotch grain”, “seville”, “bison”, etc. from such companies as S. D. Warren and in various grain depths.
  • the products of this invention substantially retain such grain pattern without the need for subsequent embossing.
  • Measurement of the broad "valley" at about the middle of the portion of skin shown in FIGS. 8 and 8A indicates a grain depth of about 30 microns.
  • the Fine and deTora application discloses and discusses various types of polyurethanes, their properties, and compounding procedures.
  • an elastomeric polyurethane as the adhesive
  • other flexible polymers may be employed.
  • an acrylic polymer emulsion such as Rohm & Haas Rhoplex N-45, applied at 56-68% solids; viscosity of say, about 1500 cps; average particle size about 0.4 - 0.5 microns.
  • water-insoluble elastomeric materials other than polyurethanes for the skin layer and for the fibers of the substrate as well as for the adhesive.
  • Such elastomers are well known in the art; see for instance, the article on "Elastomers, Synthetic” in Encyclopedia of Polymer Science and Technology Vol. 5 (1966), John Wiley & Sons, and particularly the various types of elastomers listed at page 406-420 thereof. Especially suitable are those elastomers, there listed, which are soluble and do not require subsequent vulcanization to attain high tensile strengths.
  • the fibrous substrate is pre-treated to increase its modulus and/or its resistance to tearing in a direction normal to its upper and lower surfaces.
  • This may be effected, for instance, by preimpregnating the substrate with a dilute latex (e.g. containing about 10 to 20% of dispersed polymeric adhesive) which increases the strength of the fiber-to-fiber bonds even in the portion of the sheet remote from the skin.
  • the adhesive used for this purpose may be of any suitable type such as an elastomeric polyurethane, a vinyl chloride-ethylene copolymer (e.g. Monsanto Monflex).
  • the amount of polymer so added to the sheet may represent less than 10% (e.g. 1 or 2 to 5%) of the weight of the fibrous substrate.
  • the latex-impregnated substrate is preferably assembled with the laminating adhesive layer before drying of the impregnant.
  • the wet impregnated substrate is laminated to a 1.5 mil (46 microns) thick polyurethane skin which had been preformed on release paper and coated with an 8 mil (.2 mm) thick layer of adhesive (as in Example 2). The wet impregnated substrate was laid onto the layer of adhesive.
  • the lamination is carried out by squeezing the composite (wet substrate-adhesive-skin) between sheets of release paper to a thickness of 64 mils by placing it in an area bordered by shims and rolling a heavy roller over it, the roller contacting the shims.
  • the laminate is then dried, and cured, for 4 minutes at 300° F. (149° C.).
  • the skin is coated with a very thin coating of polyamide containing a flatting agent.
  • the coating is, for example, Witco TC-1 (13% solution of polyamide in ethyl alcohol) having 2% silica flatting agent dispersed in it and was applied using a No.
  • Impranil DLH is a milky latex containing 40% anionic high molecular weight, thermoplastic, aliphatic polyester polyurethane, having a particle size of 0.1 to 0.4 microns, specific gravity of 1.1 and a viscosity of 220 cps., as measured with a Brookfield LVF type viscometer at 20° C. using Spindle #1 at 12 rpm.
  • Typical physical properties for 0.1 - 0.2 mm films formed from the Impranil DLH polyurethane are:
  • a particularly attractive appearance and texture may be imparted to the laminates by hot wrinkling, giving the material the appearance of a wrinkled or boarded leather and further improving its break.
  • This may be effected by, for instance, heating the laminate to say 250° F, letting it cool in air until it can be handled and then wrinkling and working it repeatedly by hand, or wrinkling it by stuffing it into a container, and letting it cool, say to room temperature, or (using machinery and techniques known for this purpose in the art of hot-wrinkling of polyurethane-coated fabrics) by stuffing it hot (e.g. at about 250° F) into a container and removing it therefrom after a few minutes (e.g. 10 minutes) residence time and then letting it cool.
  • a few minutes e.g. 10 minutes
  • This process is particularly effective when an elastomeric adhesive having a relative low modulus at 10% elongation is employed, such as a 10% modulus of less than 50 pounds per square inch (measured on a film cast from said adhesive) or when the elastomeric adhesive has a low softening point, such as a softening point below about preferably below 150° C.
  • an elastomeric adhesive having a relative low modulus at 10% elongation such as a 10% modulus of less than 50 pounds per square inch (measured on a film cast from said adhesive) or when the elastomeric adhesive has a low softening point, such as a softening point below about preferably below 150° C.
  • one particularly suitable adhesive (Millmaster Onyx "Polyurethane Latex 5HS”) has a 10% modulus of about 20 pounds per square inch and has a stress-strain curve (measured on said cast film) defined by the approximate data given in the following table which also includes the characteristics of an adhesive which (when employed in the same
  • the softening point range for the 5HS is relatively broad, such as 195°-250° C; for the DLN it is also wide, such as 175°-260° C.
  • elastomeric adhesives of low softening point are Mobay Chemical Corp. polyurethane latex KA8100 and KA8066; a particularly suitable adhesive is a blend of these two containing a major proportion of KA8100, such as a blend in which the ratio of KA8100 to KA8066 is about 2:1, e.g. a 70:30 blend, or about 5:1, e.g.
  • the fibers of the base sheet are substantially unswollen by the applied liquid adhesive (or are protected against swelling attack), e.g. when an aqueous latex adhesive is employed with a base of water resistant fibers.
  • the invention makes possible the production of a very lightweight, highly flexible sheet product whose surface has excellent resistance to gouging, which shows no indication of an underlying fiber pattern (such as "orange peel") even when highly stretched, and which has good seam strength without requiring any woven, knitted or needled fabric reinforcement.
  • a reinforcing fabric adhered thereto such as with a backing of stretchable fabric, e.g. circular knit fabric.
  • the product has high multidirectional stretch and conformability making it especially suitable for upholstering complexly curved modern furniture.
  • This conformability also includes an ability to recover, to a very high degree, to its original dimensions after the material has been subjected to the high strains which can occur in the use of such furniture; for instance, if the material covering the seat has poor recovery characteristics it will not have a smooth tight appearance when the sitter arises.
  • the invention has provided upholstery sheet materials having the following tensile hysteresis characteristics (measured using cycles of 3 minutes under constant strain followed by 3 minutes of relaxation):
  • the products of the invention may also be employed for other uses such as footwear and apparel.
  • the material may be made more dense and less pliable, though still relatively soft for the purpose, as described more fully later in this specification.
  • the 100% moduli of the skin, base sheet and adhesive may be determined in conventional manner, using cast films thereof, of uniform thickness and substantially free of defects.
  • Those skilled in the art are well aware of techniques for preparing such films and for testing their tensile properties (ASTM D412).
  • the elastomer solution used for the skin e.g. "WITCOBOND Y 343" 35% solution mentioned above, without the added flame retardants and pigments
  • the elastomer solution used for the skin may be cast (e.g. at a wet thickness of about 15 to 20 mils) unto a temporary support which is a smooth releasing surface, such as smooth release paper, glass, etc., then dried in circulating air ovens at say 200° F. for 2 minutes and then at higher temperatures, say 300° F.
  • the latex used for the adhesive may be cast similarly and suitably dried as by leaving it in air at room temperature overnight and then heating in an oven at say 250° F. for 1 to 2 minutes to remove residual water; since the adhesive often has the "tack" which is characteristic of a soft elastomer, it may be desirable to dust its surface as with talcum powder to facilitate handling of the dried film.
  • the solution of the polymer used to form the fibers may contain highly volatile solvent (such as the tetrahydrofuran mentioned above); in that case modifications may be desirable to insure formation of a substantially void-free uniform film.
  • a tetrahydrofuran solution of that polyurethane may ba cast similarly and immediately protected against condensation of atmospheric moisture thereon, as by placing a glass plate over (but slightly spaced from) the cast film; the thus protected wet film may then be put immediately into a vacuum chamber (e.g. at a vacuum of 30 inches of mercury and at room temperature for say 16 hours) to strip off solvent, after which residual solvent may be removed by placing the film without its upper glass protection under the same vacuum but at higher temperature, e.g. 60° C.
  • a vacuum chamber e.g. at a vacuum of 30 inches of mercury and at room temperature for say 16 hours
  • an excellent shoe upper material can be obtained by varying the impregnation or other treatment so as to produce a denser, more cohesive sheet; e.g. the process may be varied to increase the degree of penentration of the adhesive or binder into the fibrous sheet so as to increase the density of the product to at least about 0.4 g/cc, e.g. in the range of about 0.4 to 0.7 g/cc, preferably about 0.4 to 0.6.
  • FIGS. 10-15, and corresponding FIG. 10A, etc. are photomicrographs (made, as previously discussed, with a scanning electron microscope) of products suitable for shoe upper materials.
  • FIG. 10 is a cross-section as in FIGS. 1-9 of one finished shoe upper product.
  • FIG. 10A is a cross-sectional view of the product of FIG. 10, showing a corner (defined by line C--C) formed by intersection of two planar cuts which are at right angles to each other (and also at right angles to the sheet, as in FIG. 10).
  • FIGS. 10B, C and D are cross-sections of the sheet product of FIG. 10 in planes parallel to that sheet, taken at various depths (thus FIG. 10C is taken at a level about half-way between the upper and lower surfaces, FIG. 10B is taken at a level about 1/4 of the way down from the top and FIG. 10D is taken at a level about 1/4 of the way up from the bottom.
  • FIGS. 10B-1, 10C-1 and 10D-1 correspond to FIGS. 10B, 10C and 10D respectively but are at higher magnification.
  • FIGS. 10E and 10E-1 are plan views (at two different magnifications) of the finished surface of the sheet of FIG. 10.
  • FIG. 10F is an enlarged view of a portion of FIG. 10.
  • FIG. 11 is a cross-section of another sheet product, made in a different manner, suitable as a substrate (to be given a top finish).
  • FIGS. 11A and 11A-1 are plan views (at different magnifications) of a surface of the sheet of FIG. 11.
  • FIG. 11B is an enlarged view of a portion of FIG. 11.
  • FIG. 12 is a plan view of a finished surface of a product made by applying finishing materials to one surface of a sheet very similar to that shown in FIG. 11.
  • FIG. 13 is a cross-section of another sheet product suitable as a substrate.
  • FIGS. 13A, 13B and 13C are cross-sections of the sheet product of FIG. 13 is planes parallel to that sheet taken (like FIGS. 10B, C and D) at depths one fourth from the top surface (FIG. 13A), half-way between the top and bottom surfaces (FIG. 13B) and one fourth from the bottom surface (FIG. 13C).
  • FIG. 13D is a plan view of the upper surface of the sheet product of FIG. 13.
  • FIG. 14 is a cross-section of another sheet product suitable as a substrate.
  • FIG. 15 is a cross-section of still another sheet product suitable as a substrate.
  • FIG. 10 shows a product made by the use of a technique like that of Example 6. That is, the latex adhesive is applied to skin-coated release paper and then pressed against the fibrous sheet and the assemblage is passed through a nip having a predetermined gap.
  • the latex is of such low viscosity and is applied in such amount as to penetrate throughout substantially the whole thickness of the fibrous sheet.
  • the ratio of latex solids to fiber solids in the product is in the range of about 1:4 to 1:3 (e.g. the product weighs about 14.5 ox/yd 2 , its preformed skin weighs about 2 oz/yd 2 and the fibrous sheet before treatment weighs about 9.7 oz/yd 2 ).
  • FIG. 10 retains its fibrous character, as can be seen from FIGS. 10B to 10D (and 10B-1 to 10-D1) which are cross sections in planes parallel to the sheet, taken at various depths. It will be seen that the fibers substantially retain their criss-crossing direction parallel to the sheet and that there are webs or other shaped bodies of adhesive covering or bridging spaced fiber intersections. Cross-sections taken at right angles to the sheet (FIG. 10) show that in the zone below the skin the structure is similar to that seen in FIGS. 6-8. This is also shown in the view of a corner, in FIG. 10A. Unlike the structures of FIGS. 6-8, however, the binder or adhesive in FIGS.
  • the less-impregnated portion of the fibrous sheet may be similarly impregnated with binder, as by applying a latex to that flesh side so as to effect a limited impregnation thereof.
  • a binder e.g.
  • elastomeric latex from the "flesh side" so as to effect an extensive impregnation of the sheet and raise its density to above 0.4 and its overall impregnant: fiber ratio to say 1:4, 1:3 or more; this may be done, if desired, before the release paper is removed.
  • the latex-impregnated fibrous sheet is dried while bonded to a support (e.g. release paper) and the sheet is thus restrained against substantial shrinkage in area during drying of the latex.
  • a support e.g. release paper
  • FIGS. 10B-D show that, despite the presence of the bonding agent, the structure of the impregnated fibrous sheet is very open; it has numerous open pathways, between intersecting fibers, for the passage of moisture vapor.
  • the rate of moisture vapor transmission is thus governed in large part by the nature of the skin.
  • FIGS. 10 and 10A it will be seen that the skin is thin enough (e.g. about 20 to 40 microns thick) to permit the passage of water vapor even though, as shown in plan views of the top surface of the skin (FIGS. 10E and 10E-1) there are no pores which visibly (at 200 ⁇ magnification) pass through the skin.
  • the water vapor permeability of the skin may be improved by using a thinner skin (e.g.5,10 or 15 ⁇ thick). It may also be improved by effecting at least a portion of the skin-solidification step by coagulation with non-solvent for the skin material rather than evaporation; thus one may bring the aqueous latex into contact with the skin-forming layer while the latter still contains significant amounts of water-miscible solvent for the water-insoluble skin material. For instance, the step of drying the skin layer (on the release paper) in an oven prior to contact with the latex may be omitted, or the skin layer may be only partially dried, so that it still contains a substantial amount of, say, dimethyl formamide when it comes into contact with the aqueous latex.
  • the exposed surface of the skin may be given additional finishing treatments such as those conventionally employed in the art; see for instance U.S. Pat. Nos. 3,764,363, 3,481,766, 3,481,767 and 3,501,326, and note also the treatments mentioned in Example 6 above.
  • the upper skin layer may be provided, on the sheet material, after the fibrous sheet has been impregnated. That is, an impregnated sheet, having a density of at least about 0.4 g/cc, may be used as a substrate for a shoe upper material in place of the substrates conventionally employed for this purpose, e.g. impregnated needled shrunk polyester non-wovens).
  • a relatively thin layer having a thickness of, say, about 20 mils [500 microns]
  • conventional water-vapor permeable microporous elastomeric polyurethane and such microporous layer may be finished in conventional manner, as described, for instance, in U.S. Pat. Nos. 3,873,406, 3,764,363, 3,481,766, 3,481,767 and 3,501,326.
  • FIG. 11 there is shown a cross-section of a material, having a density of about 0.51 g/cc, made by impregnating the fibrous sheet material with a latex and drying the impregnated material (in which the impregnant (solids):fiber ratio is about 1:4) in a heated press having one hot face and the other face at about room temperature.
  • the photomicrograph is taken at a slight tilt so that one can see also a portion of the surface which has a highly open fibrous structure, as can be seen from the plan views (at different magnifications) in FIGS. 11A and 11A-1.
  • FIG. 11 also shows the effect of differential heating during drying; the lower portion of the sheet seen in FIG.
  • FIG. 11 was in contact with the hot face of the press and is considerably denser than the balance of the sheet; FIG. 11 indicates that the lower portion has both a higher fiber density and a higher impregnant density.
  • a skin, or a microporous layer having a skin may be placed on either the more dense or less dense side of the sheet.
  • the skin need not be of such thickness or smoothness as to conceal the underlying fibrous structure and it may in some cases have skin-traversing pores that are visible even under low magnification (e.g. at 20X).
  • One such permeable skin showing the fiber pattern is shown in plan view in FIG.
  • FIG. 12 in making this product the skin material was applied to the less dense side of the impregnated compressed sheet.
  • the product of FIG. 12 has a good break and has an attractive appearance, and feel, like pigskin; also its abrasion resistance is much better than that of the material prior to the application of the skin or finish.
  • the substrate for shoe upper material may also be produced by impregnating to a suitable degree without compressing the product during drying.
  • Various products made in this manner are show in FIGS. 13-15.
  • the ratio of binder to fiber is about 1:4 and the material is permitted to shrink in area during drying; owing to such shrinkage its unit weight (17.2 oz/yd 2 ) and density (about 0.44 g/cc) are somewhat higher than those of the material of FIG. 10 even though both impregnated products were made from fibrous sheets of similar unit weight.
  • the tongue tear strength of the material of FIG. 13, while adequate for shoe making is considerably lower than that of the product of FIG. 10.
  • FIG. 14 was also made from a fibrous sheet of unit weight of about 9.8 g/cc in a manner similar to that of FIG. 13, but using conditions to place more impregnant into the structure (the ratio of impregnant to fiber is 1:2.5); here the shrinkage in area was about 25-30%.
  • the tongue tear strength of the FIG. 14 product was higher than that of the product of FIG. 13, but somewhat lower than that of the product of FIG. 10.
  • the fibrous sheet material may be impregnated with the latex (e.g. in proportions corresponding to say about 10 to 40 parts of dry impregnant per 100 parts of fibers) and, while the impregnated sheet is still wet (prior to substantial drying) it may be pressed against an adhesive layer resting on a skin on a temporary support (such as release paper) and the shole assemblage then dried; thus the wet impregnated substrate described in Example 13 below (65.3% wet pickup of KA 8066, 22.3% dry pickup) may be used as the wet impregnated substrate of Example 9 above. Combinations of layers of different densities or binder contents may be used.
  • the substrate may have a top layer composed of a fibrous sheet impregnated with a binder of relatively high modulus (e.g. a 100% modulus of about 1000 to 2000 psi, such as KA 8066, and a lower layer impregnated with a binder of considerably lower modulus (e.g.
  • the amount of binder in each layer may be, for instance, such that the impregnant:fiber ratio is about 1:0 to 1:2.5 (such as about 1:5 or 1:4) and the top layer may contain about as much fiber as the lower layer (and be of similar thickness) or it may contain less fiber (and be correspondingly thinner) than the lower layer, e.g. about 5 to 10 (such as 7) ounces of fiber per square yard of upper layer and about 10 to 15 (such as 12) ounces of fiber per square yard of lower layer.
  • a two-layer substrate product of this type may be soft overall, owing to its more pliable binder in the lower layer, while having the very good gouge resistance of its upper layer containing the less pliable high modulus binder.
  • the two layers may be adhered by pressing them together while they are, for instance, still wet with latex impregnant, followed by drying.
  • a skin may be present on the upper layer.
  • Substrates produced in accordance with this invention exhibit a good break even without a skin layer. They also show a desirable good "roll” and a desirable round “fold.”
  • the "roll” may be observed by grasping the sheet between the thumb and forefinger of each hand, with the thumbs spaced about an inch apart, then bending the sheet so that it forms a 180° arc between the thumbs, and then moving one hand back and forth so as to move (or "roll") that arc along the sheet material; the movement occurs smoothly, without periodic variations in resistance to such movement.
  • the folding characteristics may be observed by folding the sheet and then folding it again transverse to the first fold; both folds are seen to be smooth arcs.
  • the products for use in shoe uppers are sheets of criss-crossing elastomeric fibers running parallel to the surfaces of the sheet. They contain a polymeric binder adhered to the fibers within the sheet, the weight ratio of binder to fibers being in the range of about 1:10 to 6:10 or 7:10 preferably about 2:10 to 5:10 or less.
  • the proportion and position of the binder in the sheet is such that the interior of the sheet still has a definite structure of criss-crossing fibers running parallel to the surfaces of the sheet, with open pathways between intersection fibers, and the sheet is highly porous; its pores constitute about 2/5 to 2/3or 3/4 of the volume of the sheet.
  • the proportion and position of the binder is such that irregular bodies, or matrices, of the binder surround, and are firmly bonded to, a plurality of overlying intersecting fibers (such as 3, 4 or more such fibers).
  • a plurality of overlying intersecting fibers such as 3, 4 or more such fibers.
  • FIG. 11B illustrates similar structures such as the integrated cluster 46 of multidirectional straight intersecting fibers.
  • the binder penetrates into the fiber structure as irregular meandering fingers disposed at, and joining, fiber intersections.
  • the binder itself is seen to be substantially non-porous even at high magnification (such as the 300X magnification in FIG. 10F), unlike the microporous coagulated binders customarily found in impregnated non-wovens used for shoe uppers; compare the illustrations in the article by O. Fukushima entitled "Construction of Man-Made leather” in J. Coated Fabrics Vol. 5 (July 1975) pages 3-15, notably FIGS. 2-4 at pages 8 and 9 of that article.
  • the shoe upper materials of this invention may be employed in place of leather, using conventional shoe-making techniques for men's and women's shoes, such as described in the booklet "How American Shoes Are Made” copyright 1961 by United Shoe Machinery Company.
  • Products of this invention have been found to "make up” well during lasting and related shoe making operations, to produce shoes with a comfortable soft, pliable feel and free of "orange peel” or other "show-through” effects, to show high tear strengths to other shoe components when bonded thereto with say, water based adhesives, and to behave substantially isotropically for efficient cutting of shoe upper sections.
  • This Example describes the making of the product of FIG. 10. It uses a technique like that of Example 6. That is, the latex adhesive is applied to skin-coated release paper and then pressed against the fibrous sheet and the assemblages is passed through a nip having a predetermined gap. However, in this example the adhesive latex is of such low viscosity and is applied in such amount as to penetrate throughout substantially the whole thickness of the fibrous sheet.
  • a fibrous substrate as in Example 1 weighing about 9.7 oz/yd 2 and having a thickness of about 52 mils is laminated to a preformed polyurethane skin (1.5 mil thick) on release paper using an aqueous dispersion of anionic polyurethane.
  • the skin is formed by coating the release paper with a 9 mils (wet) film of polyurethane solution having a viscosity of 7400 centipoises (Brookfield LVF, spindle #4, 30 rpm at STP) and consisting of a 35% solution of light stable aliphatic polyurethane (as described on page 12 of Ser. No. 512,265) and evaporating solvent from the film.
  • the aqueous adhesive consisting of 30 parts KA8066, 1.9 parts Inpranil P.W., and 1.8 parts of water, is then applied as a 12 mils (wet) layer to the preformed skin and the fibrous substrate is laid into the wet adhesive. Then the composite of fibrous substrate, adhesive, preformed skin, and release paper is passed between the nip rolls of a laminator set at a 25 mils gap and then through a 35 ft., 225° F. (118° C.) oven at the rate of 12 ft. per minute, i.e. a residence time of about 3 minutes. The release paper is then removed from the laminate.
  • the release paper used is S. D.
  • the product of FIG. 11 which is about 64 mils (1.63 mm) thick is prepared by laminating together two wet impregnated fibrous sheets. Prior to impregnation each fibrous sheet, as in Example 1, is about 55.3 mils (1.4 mm.) thick and has a density of 0.234 gms/cc.
  • the laminating is carried out by laying one sheet on top of the other and impregnating the composite with a 30% aqueous solution of linear polyurethane made by diluting polyurethane latex KA 8066 (Mobay Chemical Co.) with water.
  • the amount of impregnant pick up is 23.4% (dry basis) based on the weight of composite.
  • the impregnated composite is placed between sheets of release paper and then compressed to a thickness of 64 mils (1.63 mm) in a heated press, for 90 seconds with the top platen of the press set at 320° F. (160° C.) and the bottom platen set at 110° F. (38° C.).
  • the laminate is then removed from the press and heated at 250° F. (121° C.) for 5 minutes to remove residual water.
  • the resulting footwear substrate may be finished by any suitable method, e.g., spraying, printing, or by lamination of a skin or foil to one side, to obtain a finished material suitable for shoe uppers.
  • the sheet product has a tensile strength (lb. per inch of width) of about 60M, 86T; an elongation at break of 364% M, 400T; the forces (pounds per inch of width) needed to stretch the material are as follows: 5% stretch, 5.3 M 6.8 T; 25%, 10 M 13.2 T; 100%, 18 M 22.5 T; 300%, 46 M, 57 T; and its trapezoidal tear strength (lbs.) is 28M, 26T.
  • the product of FIG. 12 is prepared from an impregnated pressed composite like that of Example 11. Before drying the compressed wet composite, it is intaglio printed (two passes from an engraved print roll having 120 lines per inch) with a brown pigmented 10% solution of elastomeric polyurethane in dimethyl formamide. It is then dried for five minutes in hot air at 250° F (121° C), then printed again in the same way and again dried for 5 minutes at 250° F, then printed successively with a similar elastomeric polyurethane solution (in a darker red color) and with a clear elastomeric light-resistant polyurethane solution, being dried between prints.
  • This Example describes the making of the product of FIG. 13.
  • the wet impregnated substrate is dried in a hot air oven for 10 minutes at 300° F. (140° C.) During drying the impregnated material shrinks in area about 25%.
  • the sheet product has a tensile strength (lbs. per inch of width) of about 43; an elongation at break of about 350%; the forces (pounds per inch of width) needed to stretch the material are approximately as follows: 5% stretch, 3.4; 25%, 7.3; 100%, 14.3; 300%, 35.5; and its tongue tear strength (lbs.) is about 5.9 M 6.1 T.
  • the product of FIG. 14 is produced as in Example 13 except that the padder is adjusted so that the dry pickup is about 40%.
  • the sheet product has a tensile strength (lbs per inch of width) of about 43 M, 51 T; an elongation at break of about 360 M, 360 T; the forces (pounds per inch of width) needed to stretch the material are approximately as follows: 5% stretch, 3.8 M, 5.1 T; 25%, 8.2 M, 9.7 T; 100%, 14.9 M, 16.5 T; 300%, 35.2 M, 40.8 T; and its tongue tear strength (lbs.) is about 7.6 M, 7.7 T.
  • the product of FIG. 15 is produced as in Example 13 using a fibrous substrate, as in Example 1, 89.4 mils (2.27 mm) thick and weighing 15 oz/yd. 2 (0.224 g./cc).
  • the dry pickup is about 42% and the shrinkage in area is less than 20%.
  • the sheet product has a tensile strength (lbs. per inch) of width) of about 80; an elongation at break of about 420%; the forces (pounds per inch of width) needed to stretch the material are approximately as follows: 5% stretch, 5.4; 25%, 12.3; 100%, 21.2; 300%, 49.2; and its tongue tear strength (lbs) is about 11.7 M, 11.9 T.
  • the product will usually have a thickness in the range of about 0.8 to 2.0 mm, preferably in the range of about 0.9 to 1.8 mm.
  • the products of the Examples have the following approximate thicknesses:

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Laminated Bodies (AREA)
  • Synthetic Leather, Interior Materials Or Flexible Sheet Materials (AREA)
  • Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
US05/616,714 1974-10-04 1975-09-25 Sheet material Expired - Lifetime US4076879A (en)

Priority Applications (2)

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CA237,018A CA1079170A (fr) 1974-10-04 1975-10-03 Procede de fabrication de simili-cuir souple
US05/881,102 US4229472A (en) 1974-10-04 1978-02-24 Sheet material

Applications Claiming Priority (1)

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US51226574A 1974-10-04 1974-10-04

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US51226574A Continuation-In-Part 1974-10-04 1974-10-04

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JP (1) JPS5163880A (fr)
AR (1) AR210095A1 (fr)
BE (1) BE834157A (fr)
BR (1) BR7506319A (fr)
CS (1) CS235055B2 (fr)
DD (1) DD121064A5 (fr)
DE (1) DE2544368A1 (fr)
DK (1) DK448175A (fr)
ES (1) ES441490A1 (fr)
FR (2) FR2292586A1 (fr)
GB (2) GB1534012A (fr)
IN (1) IN144764B (fr)
LU (1) LU73514A1 (fr)
NL (1) NL7511630A (fr)
SU (1) SU591155A3 (fr)
ZA (1) ZA756053B (fr)

Cited By (6)

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US4181450A (en) * 1976-04-02 1980-01-01 Akzona Incorporated Erosion control matting
US4229472A (en) * 1974-10-04 1980-10-21 Inmont Corporation Sheet material
US4655868A (en) * 1983-08-26 1987-04-07 Kuener Textilwerke GmbH Top cloth for articles of clothing as well as a manufacturing process and transfer unit for it
US20050025954A1 (en) * 2003-07-30 2005-02-03 Sullivan Alfred Hardy Cloth backing for use in a trim cover
ITMI20110946A1 (it) * 2011-05-26 2012-11-27 Francis Fanelli Metodo di produzione e film plastico a stampa indiretta
CN112646353A (zh) * 2020-12-16 2021-04-13 航天科工武汉磁电有限责任公司 一种抗冲击蒙皮的制备方法、抗冲击吸波板及其制备方法

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EP0453598A1 (fr) * 1990-04-25 1991-10-30 Kabushiki Kaisha Toshonishiwaki Structure étanche à l'eau

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US3481767A (en) * 1966-01-12 1969-12-02 Du Pont Process for applying a polyurethane finish composition to synthetic microporous polymeric materials
US3483069A (en) * 1965-08-23 1969-12-09 Little Inc A Polyurethane foam reinforced fibrous article and method of forming the same
US3501326A (en) * 1965-09-24 1970-03-17 Du Pont Glossy microporous sheet material
US3574106A (en) * 1968-10-02 1971-04-06 Plymouth Rubber Co Inc Leather-like laminated sheet materials
US3620811A (en) * 1969-11-03 1971-11-16 Goodrich Co B F Supple poromeric laminate
US3634184A (en) * 1968-06-06 1972-01-11 Tenneco Chem Elastomeric film and products therefrom
US3687715A (en) * 1969-04-24 1972-08-29 Teijin Ltd Articifial leather having polyurethane surface finish layer
US3764363A (en) * 1969-07-22 1973-10-09 Inmont Corp Surface treatment of microporous surface of sheet material and product produced
GB1383597A (en) 1971-02-19 1974-02-12 Inmont Corp Fibrous products
US3873406A (en) * 1972-12-22 1975-03-25 Toray Industries Synthetic leather and method of preparing the same
US3914501A (en) * 1969-06-27 1975-10-21 Union Carbide Corp Porous products and processes therefor

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FR1411110A (fr) * 1964-05-27 1965-09-17 Rhodiaceta Procédé pour la fabrication d'un matériau souple, perméable à l'air et à la vapeur d'eau, et produit obtenu selon ce procédé
GB1152543A (en) * 1966-05-20 1969-05-21 Toyo Tire & Rubber Co Method of producing Artificial Leathers and product of the same
FR1531021A (fr) * 1966-07-11 1968-06-28 Ici Ltd Feuilles perméables à la vapeur
US3607481A (en) * 1966-09-19 1971-09-21 Toyo Rayon Co Ltd Process for production of synthetic leather
DE1778925A1 (de) * 1967-06-22 1971-08-19 Kurashiki Rayon Co Flachmaterial und Verfahren zu seiner Herstellung
DE1619252C3 (de) * 1967-10-19 1978-04-06 Enka Ag, 5600 Wuppertal Kunstleder und Verfahren zur Herstellung desselben
DE1619253C3 (de) * 1967-12-20 1975-10-16 Enka Glanzstoff Ag, 5600 Wuppertal Verfahren zur Herstellung von Kunstleder
US3663266A (en) * 1970-05-21 1972-05-16 Du Pont Moisture responsive synthetic microporous sheet material

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US3460969A (en) * 1965-08-18 1969-08-12 Goodrich Co B F Process for producing microporous coatings on a textile fabric
US3483069A (en) * 1965-08-23 1969-12-09 Little Inc A Polyurethane foam reinforced fibrous article and method of forming the same
US3501326A (en) * 1965-09-24 1970-03-17 Du Pont Glossy microporous sheet material
US3481767A (en) * 1966-01-12 1969-12-02 Du Pont Process for applying a polyurethane finish composition to synthetic microporous polymeric materials
US3634184A (en) * 1968-06-06 1972-01-11 Tenneco Chem Elastomeric film and products therefrom
US3574106A (en) * 1968-10-02 1971-04-06 Plymouth Rubber Co Inc Leather-like laminated sheet materials
US3687715A (en) * 1969-04-24 1972-08-29 Teijin Ltd Articifial leather having polyurethane surface finish layer
US3914501A (en) * 1969-06-27 1975-10-21 Union Carbide Corp Porous products and processes therefor
US3764363A (en) * 1969-07-22 1973-10-09 Inmont Corp Surface treatment of microporous surface of sheet material and product produced
US3620811A (en) * 1969-11-03 1971-11-16 Goodrich Co B F Supple poromeric laminate
GB1383597A (en) 1971-02-19 1974-02-12 Inmont Corp Fibrous products
US3873406A (en) * 1972-12-22 1975-03-25 Toray Industries Synthetic leather and method of preparing the same

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4229472A (en) * 1974-10-04 1980-10-21 Inmont Corporation Sheet material
US4181450A (en) * 1976-04-02 1980-01-01 Akzona Incorporated Erosion control matting
US4655868A (en) * 1983-08-26 1987-04-07 Kuener Textilwerke GmbH Top cloth for articles of clothing as well as a manufacturing process and transfer unit for it
US20050025954A1 (en) * 2003-07-30 2005-02-03 Sullivan Alfred Hardy Cloth backing for use in a trim cover
ITMI20110946A1 (it) * 2011-05-26 2012-11-27 Francis Fanelli Metodo di produzione e film plastico a stampa indiretta
CN112646353A (zh) * 2020-12-16 2021-04-13 航天科工武汉磁电有限责任公司 一种抗冲击蒙皮的制备方法、抗冲击吸波板及其制备方法

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FR2292586A1 (fr) 1976-06-25
DK448175A (da) 1976-04-05
AR210095A1 (es) 1977-06-30
ES441490A1 (es) 1977-08-16
BR7506319A (pt) 1976-08-10
GB1534012A (en) 1978-11-29
NL7511630A (nl) 1976-04-06
DE2544368A1 (de) 1976-04-22
SU591155A3 (ru) 1978-01-30
BE834157A (fr) 1976-04-05
DD121064A5 (fr) 1976-07-12
LU73514A1 (fr) 1976-08-19
FR2326291A1 (fr) 1977-04-29
JPS5163880A (en) 1976-06-02
CS235055B2 (en) 1985-04-16
ZA756053B (en) 1976-09-29
GB1534011A (en) 1978-11-29
AU8518075A (en) 1977-03-31
IN144764B (fr) 1978-07-01

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